1. Field of the Invention
This invention relates in general to data storage systems and more particularly relates to vibration reduction systems within a data storage system.
2. Description of the Related Art
Data storage systems generally include the hardware necessary to store and retrieve data within a computer system. Often data storage systems include a plurality of disk drive assemblies mounted in a two dimensional array (i.e., multiple rows and columns) within an enclosure or support structure. One problem typically encountered in data storage systems with multiple disk drive assemblies is rotational vibration. Rotational vibration caused by mechanical movement within a disk drive assembly is transferred to neighboring disk drive assemblies through the enclosure, disrupting read/write functions and limiting the overall performance of the data storage system.
FIG. 1A illustrates a typical data storage system 100. The data storage system 100 includes an enclosure 102 and a disk drive assembly 104. The mechanical components of the disk drive assembly 104 are typically mounted within a carrier 106. The carrier 106 accordingly engages side walls 108 of the enclosure 102. Furthermore, the enclosure 102 comprises a backplane 110 that includes one or more backplane connectors 112. The backplane connectors 112 provide power to the disk drive assemblies 104 and allow data signals to be exchanged with a computer system.
FIG. 1B illustrates a typical disk drive assembly 104 with a cut away view of a hard disk drive 114. The hard disk drive 114 comprises the mechanical components of the disk drive assembly 104. For clarity, the term “disk drive” as used herein refers to the entire disk drive assembly 104, unless otherwise stated.
The hard disk drive 114 of the disk drive assembly 104 is housed in a carrier 106. The depicted carrier 106 is a box-like structure that provides support and ventilation to the mechanical components of the hard disk drive 114. Additionally, the hard disk drive 114 is connected to other computer system components through a backplane connector 116 that connects to a corresponding connector 112 of an enclosure 102 (FIG. 1A). The carrier 106 further includes opposing side plates 118 and a plurality of support points 120 disposed along the side plates 118. Typically, the support points 120 contact or engage the walls of the enclosure 102.
Within the hard disk drive 114, a rotary actuator 122 moves one or more arm assemblies 124 with a head containing read/write elements over data tracks on disk media 126. During seek operations, the actuator 122 selectively positions the head of an arm assembly 124 over the desired data tracks of the disk 126. Typically, the disk 126 is rotating while the actuator 122 pivots, swinging the arm 124 back and forth across the plane of the spinning disk 126. Accurate positioning of the read/write element is essential to the functionality of the hard disk drive 114. However, while the arm assembly 124 is being positioned, the torque, or rotational force created by the movement of the arm assembly 124, causes rotational vibration that is transmitted to the enclosure 102 and adjacent disk drive assemblies 104.
Rotational vibration transmitted to a disk drive assembly 104 can prevent accurate positioning of the head and read/write elements. Misalignment of the head consequently slows read/write operations and reduces data throughput. In addition, rotational vibration can further cause unrecoverable errors, premature disk drive failures, and mechanical wear on moving disk drive components. Problems resulting from rotational vibration are accentuated in data storage systems 100 with multiple disk drive assemblies 104. Thus, data storage systems 100 that reduce transmission of rotational vibration have a distinct advantage over conventional systems.
Referring now to FIG. 1A, the enclosure 102 supports and constrains the disk drive 104 during operation to minimize rotary motion 125. Proper constraint of the disk drive assembly 104 during operation facilitates efficient seek performance when accessing data. The support points 120 of the carrier 106 help constrain the disk drive 104. In addition, the backplane 110 of the enclosure 102 also helps prevent the drive 104 from rotating or rocking.
Generally, the support points 120 are rigidly attached to side plates 118 at each corner of the disk drive carrier 106 to constrain the rotary motion 125 of the disk drive 104. Unfortunately, by constraining the disk drive 104 with multiple support points 120, the rotary motion 125 of the hard disk drive 114 transfers torque forces 127 to the enclosure 102. The transmitted torque forces 127 cause torsion, or twisting, in the side walls 108 of the enclosure 102. The affected enclosure 102 consequently transmits rotational vibration to other disk drive assemblies 104 stored with the data storage system 100.
To prevent transmission of rotational vibration, side plates 108 typically require damping and reinforcement. In the data storage system 100, damping plates 128 and ribs 130 dampen the rotational vibration and strengthen the walls 108. The additional stiffening and damping components, however, occupy valuable space within the data storage system 100 and increase material and manufacturing costs.
From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that effectively reduce rotational vibration transmission within a data storage system. Beneficially, such an apparatus, system, and method would specifically overcome the known problems related to excessive rotational vibration transmitted within an enclosure to disk drive assemblies. In addition, the apparatus, system, and method should be cost effective, easy to implement, and should conserve space within the data storage system.